The referee and assistant referees should wear black or white
clothing/shoes and avoid reserved colors for the ball, the goals, and
player markings in their clothing. The referee and his/her assistants
will be close to but off the field during play. The referee and the
assistants may enter the field in particular situations, e.g. to
reposition the robot when applying a penalty or stuck. The referee and
his/her assistants should avoid interfering with the robots as much as
possible.